November 1999
Intermediate to advanced
832 pages
19h 28m
English
Content preview from Practical Programming in Tcl & Tk, Third EditionBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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The Scale Widget
The scale widget displays a slider in a trough. The trough represents a range of numeric values, and the slider position represents the current value. The scale can have an associated label, and it can display its current value next to the slider. The value of the scale can be used in three different ways:
Explicitly get and set the value with widget commands.
Associate the scale with a Tcl variable. The variable is kept in sync with the value of the scale, and changing the variable affects the scale.
Register a Tcl command to be executed after the scale value changes. You specify the initial part of the Tcl command, and the scale implementation adds the current value as another argument to the command.
Example 29-5 A scale widget. ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.